The present disclosure relates to a method for processing a product by phase separation. The present disclosure thus relates to a method for the continuous processing of a product such as a vegetable or animal oil or fat, the processing occurring via a separation into two liquid phases and a slides phase. The method step includes processing the product, the processing occurs in a centrifuge arranged as a separator, the separator including a rotatable drum, a disk stack having risers arranged in the drum, a product feed having a feed tube, a first separator disk to discharge a lighter liquid phase from the drum, a second separator disk to discharge a heavier liquid phase from the drum, a solids discharge opening to discharge a solids phase from the drum, and a separator zone formed between the lighter phase and the heavier phase in the separator.
DE 10 2005 021 331 A1, DE 697 12 569 T2 and WO 94/06 565 A1 are mentioned concerning the technological background. Although DE 10 2005 021 331 A1 shows a purifier, discharge of a heavier liquid phase occurs by an outlet to which a throttle device is assigned and only the discharge of a lighter liquid phase by a separation disk. WO 94/06 565 A1 discloses a purifier in which the lighter liquid phase occurs by a separation disk and the other, heavier liquid phase occurs by a discharge apparatus using small tubes obliquely adjustable in relation to the radial, which small tubes are set once to the desired radius, so that the discharge of this phase will always occur in operation, but such that only a part of the small tubes immerses into the heavy phase, which is intended to keep friction at a low level. DE 697 12 569 T2 discloses a purifier in which the lighter liquid phase occurs by a baffle plate and the other heavier liquid phase by an outlet element which is pressed by a drive apparatus to varying locations of a free liquid surface area. That is so that the discharge of this phase will also always occur in operation, wherein the immersion depth in this phase shall be kept constant to the highest possible extent in order to reduce power consumption. In accordance with DE 103 61 520 B2, blockages in the flow paths are prevented in processing by temporary displacement of the separation zone between skimmed milk and cream by throttling a valve or by increasing the feed capacity.
In the operation of purifiers, problems with the continuous discharge of the heavier phase will occur especially when the fraction of the heavier phase relative to the lighter phase is such that its viscosity in operation can increase strongly at a point in time that cannot be determined temporarily in a precise way.
Such an effect will occur, for example, in the processing of vegetable and animal oils and fats, which occurs in the separation of soapstock or mucilaginous substances, such as phosphatides.
These attendant materials strongly reduce the durability of oils and fats and should, therefore, be separated. There are hydratizable and non-hydratizable phosphatides. The attendant materials are removed, in that they are suitably treated and hydratized with acids, alkaline solutions, water and/or other substances. As a result, they lose their lipophil character, will become oil-insoluble, are precipitated from the oil and, after such pre-treatment, can, therefore, be separated in the separator.
The embodiments of the present disclosure address the solving of the above-noted problems and effects in a simple way.
Thus, embodiments of the present disclosure relate to a method for the continuous processing of a product such as a vegetable or animal oil or fat. The processing occurs via a separation into two liquid phases and a solids phase. The method steps include: processing the product, the processing occurring in a centrifuge arranged as a separator, the separator including a rotatable drum, a disk stack having risers arranged in the drum, a product feed having a feed tube, a first separator disk to discharge a lighter liquid phase from the drum, a second separator disk to discharge a heavier liquid phase from the drum, a solids discharge opening to discharge a solids phase from the drum, and a separator zone formed between the lighter phase and the heavier phase in the separator; and, adjusting a discharge radius from discharging the heavier liquid phase when a viscosity of the heavier liquid phase exceeds a limit value. Thus, when the viscosity of the heavier liquid phase HP increases substantially the inlet of the separator element for the heavier liquid phase is pivoted to a larger diameter in order to discharge the collected liquid phase of increased viscosity to a radius disposed further outside in the drum. After the discharge of the highly compacted liquid up to the radius set with the associated separator element, or disk, the separator element, or disk, will be set back a smaller radius again by discharging the heavier liquid phase.
The varying feed pressure in the product feed is determined as an indicator for the rise in the viscosity in the heavier liquid phase or the discharge pressure of the lighter liquid phase exceeds a threshold value, or if the gradient of the feed or discharge pressure is too large, the second separator element, or disk, will be adjusted to the above-mentioned larger radius.
Embodiments of the present disclosure are discussed herein and in the appended claims.
Other aspects of the present disclosure will become apparent from the following descriptions when considered in conjunction with the accompanying drawings.